Chicago ? Inside the cells of your pet cat lies a history book, a story that stretches back to when humans first settled into civilizations and discovered agriculture.

Using DNA from modern house cats, researchers have traced the origin of domestic cats to a specific time and region that coincided with the settlement of humans in the Middle East known as the Fertile Crescent.

The finding, to be published in today’s edition of the journal Science, adds clarity to the evolutionary history of cats, a domestic animal unique in its persistent similarity to its wild ancestor. This ancestor was a particular species of wildcat native that still lives in the same region, which is now Israel.

“The evidence tells us that cats from throughout the entire world have a single common ancestor,” said study author Carlos Driscoll.

Scientists have long debated whether cats were independently domesticated at several regions and points in time, or whether they were first kept as pets in one civilization before being spread around the world. The identification of a single ancestral species for modern house cats supports the single-origin theory.